On-line optimal reactive power flow by energy loss minimization

A method for online application of optimal reactive power dispatch based on total energy loss minimization (ELM) is presented. In this approach the total energy loss from the present instant over the next hour is minimized. The method uses the load forecast during this period. All the continuous and discrete control variables are adjusted on an hourly basis. During the hour, any voltage constraint violations are removed by adjusting the VArs/voltages of generators every 15 minutes. A detailed study of a sample network is given. The ELM and power loss minimization (PLM) methods are compared by using the sample network. As seen in simulation results, the voltage profile from the ELM method is more satisfactory than that from the PLM method. In addition, the total energy loss during the specified hour which is found from the ELM method is lower than that from the PLM method. Finally, the proposed method is more likely to find feasible solutions, while the PLM method can have difficulty doing so